It has been well documented that alcohol interferes adversely with spermatogenesis in humans and rodents. This effect of alcohol might be mediated by interference with Sertoli cell or epididymal function. Our investigation will be focused mainly on the effects of alcohol on Sertoli cell function, since these cells are vital to the spermatogenic process. The objectives will be met by utilizing techniques developed in our laboratory for the isolation of human and rat Sertoli cells. The effect of alcohol on biochemical markers of Sertoli cell function will be assessed. The markers included androgen binding protein (ABP), transferrin, plasminogen activator and lactate. In addition, we intend to investigate in rats the effects of ethanol ingestion on Sertoli cell marker proteins (ABP in the epididymis, transferrin in seminal fluid), FSH receptors in the testes and FSH and testosterone levels in serum. We will also determine if ethanol ingestion affects epididymal function by quantitating the concentration of nuclear and cytoplasmic testosterone receptors in this tissue.